Attempt by two congressional staffers to contact former M16 officer highlights fight for control over House intelligence committees investigation

Two US congressional staffers who travelled to London in July and tried to contact former British intelligence officer Christopher Steele, were sent by a longstanding aide to Devin Nunes, the chairman of the House intelligence committee and a close ally of the White House.

The trip has brought back to the surface a continuing struggle for control of the committees investigation into Moscows role in the 2016 US election. The reliability of a dossier compiled by Steele, containing explosive allegations of extensive secret collusion between Trump and the Kremlin, is a key part of that investigation.

The two staffers turned up unannounced at Steeles lawyers offices while the former MI6 officer was in the building, according to a report by Politico on Friday. But the committees leading Democrat, Adam Schiff, said on Sunday neither he nor his Republican counterpart had been informed about the staffers London trip.

A congressional official insisted, however, that the staffers were in London on official committee business. He said they had been told to make contact with Steeles lawyers, rather than Steele himself.

It was an intelligence committee trip although going to meet with the lawyer was not the sole purpose of the trip. They were also there on other committee business, the official said, but he added he could not describe what else the committee staffers were doing in London.

Them being sent to meet with the lawyers was at the behest of the committee staff director, the official added, speaking anonymously because of the sensitivity of the subject.

The House intelligence committees staff director is Damon Nelson, who worked as deputy chief of staff for Devin Nunes from 2003 until 2014 and then as a senior adviser before moving in 2015 to the staff of the committee which Nunes chairs. Nunes was a member of Trumps transition team on security and enraged Democrats by maintaining close contact with the president and making a secret visit late at night to the White House in March to view supposedly secret information without telling other committee members.

Nunes stepped aside from the committees Russia investigation in April, months before the London trip, after becoming the subject of an inquiry by the House ethics panel into whether he disclosed classified information in a bid to discredit the Obama administration. Republican congressman Mike Conaway took over Nunes duties directing the Russia inquiry. Schiff, the ranking Democrat on the committee, has since praised Conaways cooperation into investigating the links between the Trump campaign and Moscow, but has also complained that Nunes has continued to intervene in the investigation, despite his understanding to stay out of it pending the ethics inquiry.